It is common practice for liquid products of the type in question to be bottled in containers of which the structure can be manufactured from multilayer or treated paper material, such as paperboard or cardboard coated with one or more layers of food-safe material suitable for liquids.
The containers in question are fashioned in most cases from flat blanks cut generally from a roll of material and bent as necessary along strategically placed crease lines to a shape suitable for holding a liquid product.
As a rule, such containers present a tubular configuration of substantially square cross section.
The containers are manufactured using conventional machines such as will bend the flat blank to create a tubular element presenting an open top end and an open bottom end.
Initially, the containers are advanced through various processing stations equipped with mechanical arms by which the edges of the open bottom end of the tubular element are bent and folded so as to enclose the end. In practice, the arms are arranged in sets, each designed to perform a particular operation on the edges of the container. The arms are also equipped with heat seal plates positioned to engage selected points of the resulting end folds and thus render the closure permanent.
The partially enclosed container is then placed in a filling station, where a liquid product will be directed in through the open top end. Thereafter, the top end is closed by bending the relative edges and securing the folds in same way as for the bottom end already described above.
Machines of the type in question present a notable drawback deriving from the excessive bulkiness of the components by which the folds of the container are bent and secured. In effect, the containers need to be transferred from one station to another by a conveyor, consisting generally in a belt passing through the various forming stations. This means that the belt must necessarily be of a certain length in order to pass through all the different stations, and consequently that considerable space is taken up by the system.
Moreover, the mechanical arms are particularly cumbersome precisely by reason of the numerous movements they have to complete, and an appreciable amount of operating space is therefore required.
The object of the present invention, accordingly, is to provide a system for forming containers, in particular containers for food products, featuring compact dimensions and occupying minimal space.
More exactly, it is an object of the invention to provide a system for forming containers, in particular containers for food products, such as will allow of optimizing the spaces utilized in closing and sealing the open end of the container.
A further object of the present invention is to minimize the space needed in order to accommodate the mechanism by which the containers are conveyed.